The spherical resin particle have been used in various fields such as filler, flame retardant, abrasive, pore forming material, spacer, and carbon material precursor, due to its characteristics. The spherical particle of furan resin is one kind of such spherical resin particles and obtained using furan as a starting material. JP-A-2007-66669 discloses that the spherical particles of furan resin are produced by the reaction of a furan compound such as furfural or furfuryl alcohol and aldehyde such as formaldehyde or paraformaldehyde. Although the use of the spherical particles of furan resin as an electrode material of battery is discussed therein, a harmful substance, i.e., aldehyde such as formaldehyde, is used as a starting material. Thus, careful consideration should be given to work environment as well as the reaction condition with a furan compound such as furfuryl alcohol.
JP-A-2007-63377 discloses a process for producing a furan resin using aldehyde such as formaldehyde or paraformaldehyde together with a furan compound such as furfural or furfuryl alcohol, in which addition condensation reaction is conducted by irradiating the reaction system with ultrasonic waves in order to obtain spherical resin nanoparticles. In this process, in addition to the problems caused by the use of aldehyde such as formaldehyde, there is another problem that the reaction system should be irradiated with the ultrasonic waves, which requires a special apparatus for the irradiation.